DATABASE & DRUG INTERACTIONS CORE There is a pressing need for a data base that contains relevant quantitative information on combinations of drugs of abuse. The Center for Substance Abuse Research (CSAR) of Temple University is proposing this effort as a new core activity in the Center activities that will be directed by RJ Tallarida. Dr. Tallarida has studied and published extensively in the area of drug combinations That effort, coupled with his numerous worldwide publications on drug combinations, is the basis of new component in this grant renewal application. Many drug combinations are well known for their approved use as well as their use on the street, (e.g., fentanyl + cocaine, heroin + methamphetamine, etc, and extensive combinations that involve alcohol or marijuana). We propose the addition of this core activity that will undertake the development of a data base derived from publications of laboratory-based studies and human use that include drug combinations of special relevance. By that we mean the legitimate medical use of a drug combination as well as common street combinations. The main objective is to search world wide and classify interactions as synergistic, sub-additive or simply additive. This will be accomplished from a newly created website, accessible by all, from our Center on Substance Abuse Research Investigators who study combinations of drugs of abuse are usually guided by awareness of those combinations that are common in street use. The patterns of such drug abuse are well known among law enforcement and regulatory agencies, and it is well documented that many-in fact, all, are potentially dangerous combinations. The danger is enhanced when the drugs interact synergistically in some toxic endpoint. It is therefore especially important to have precise quantitative information on such unusual interactions among these agents that are used recreationally and illegally.